Excretion#

QSDsan: Quantitative Sustainable Design for sanitation and resource recovery systems

This module is developed by:: Yalin Li <mailto.yalin.li@gmail.com>

This module is under the University of Illinois/NCSA Open Source License. Please refer to https://github.com/QSD-Group/QSDsan/blob/main/LICENSE.txt for license details.

class qsdsan.sanunits._excretion.Excretion(ID='', ins: Sequence[Stream] | None = None, outs: Sequence[Stream] | None = (), thermo=None, init_with='WasteStream', waste_ratio=0, **kwargs)#

Estimation of N, P, K, and COD in urine and feces based on dietary intake for one person based on Trimmer et al.

Parameters:: waste_ratio (float) – A ratio in [0, 1] to indicate the amount of intake calories and nutrients (N, P, K) that is wasted.

Examples

bwaise systems

References

[1] Trimmer et al., Navigating Multidimensional Social–Ecological System Trade-Offs across Sanitation Alternatives in an Urban Informal Settlement. Environ. Sci. Technol. 2020, 54 (19), 12641–12653. https://doi.org/10.1021/acs.est.0c03296.

property Ca_fec#: [float] Calcium excreted in feces, [g Ca/cap/d].

property Ca_ur#: [float] Calcium excreted in urine, [g Ca/cap/d].

F_BM: dict[str, float]#: All bare-module factors for each purchase cost. Defaults to values in the class attribute _F_BM_default.

F_D: dict[str, float]#: All design factors for each purchase cost item in baseline_purchase_costs.

F_M: dict[str, float]#: All material factors for each purchase cost item in baseline_purchase_costs.

F_P: dict[str, float]#: All pressure factors for each purchase cost item in baseline_purchase_costs.

property K_cal#: [float] Potassium intake relative to caloric intake, [g K/1000 kcal].

property K_exc#: [float] Potassium excretion factor, [% of intake].

property K_ur#: [float] Potassium recovered in urine, [wt%].

property Mg_fec#: [float] Magnesium excreted in feces, [g Mg/cap/d].

property Mg_ur#: [float] Magnesium excreted in urine, [g Mg/cap/d].

property N_exc#: [float] Nitrogen excretion factor, [% of intake].

property N_fec_NH3#: [float] Reduced inorganic nitrogen in feces, modeled as NH3, [% of total feces N].

property N_prot#: [float] Nitrogen content in protein, [wt%].

property N_ur#: [float] Nitrogen recovered in urine, [wt%].

property N_ur_NH3#: [float] Reduced inorganic nitrogen in urine, modeled as NH3, [% of total urine N].

property P_exc#: [float] Phosphorus excretion factor, [% of intake].

property P_prot_a#: [float] Phosphorus content in animal protein, [wt%].

property P_prot_v#: [float] Phosphorus content in vegetal protein, [wt%].

property P_ur#: [float] Phosphorus recovered in urine, [wt%].

baseline_purchase_costs: dict[str, float]#: All baseline purchase costs without accounting for design, pressure, and material factors.

design_results: dict[str, object]#: All design requirements excluding utility requirements and detailed auxiliary unit requirements.

property e_cal#: [float] Caloric intake, [kcal/cap/d].

property e_exc#: [float] Energy excretion factor, [% of intake].

property e_fec#: [float] Percent of excreted energy in feces, [%].

equipment_lifetime: int | dict[str, int]#: Lifetime of equipment. Defaults to values in the class attribute _default_equipment_lifetime. Use an integer to specify the lifetime for all items in the unit purchase costs. Use a dictionary to specify the lifetime of each purchase cost item.

property fec_exc#: [float] Feces generated per day, [g/cap/d].

property fec_moi#: [float] Moisture (water) content of feces, [wt%].

heat_utilities: tuple[HeatUtility, ...]#: All heat utilities associated to unit. Cooling and heating requirements are stored here (including auxiliary requirements).

installed_costs: dict[str, float]#: All installed costs accounting for bare module, design, pressure, and material factors. Items here are automatically updated at the end of unit simulation.

line: str = 'Excretion'#: class-attribute Name denoting the type of Unit class. Defaults to the class name of the first child class

property p_anim#: [float] Animal protein intake, [g/cap/d].

property p_veg#: [float] Vegetal protein intake, [g/cap/d].

parallel: dict[str, int]#: Name-number pairs of baseline purchase costs and auxiliary unit operations in parallel. Use ‘self’ to refer to the main unit. Capital and heat and power utilities in parallel will become proportional to this value.

power_utility: PowerUtility#: Electric utility associated to unit (including auxiliary requirements).

prioritize: bool#: Whether to prioritize unit operation specification within recycle loop (if any).

purchase_costs: dict[str, float]#: Itemized purchase costs (including auxiliary units) accounting for design, pressure, and material factors (i.e., F_D, F_P, F_M). Items here are automatically updated at the end of unit simulation.

responses: set[bst.GenericResponse]#: Unit design decisions that must be solved to satisfy specifications. While adding responses is optional, simulations benefit from responses by being able to predict better guesses.

run_after_specifications: bool#: Whether to run mass and energy balance after calling specification functions

property ur_exc#: [float] Urine generated per day, [g/cap/d].

property ur_moi#: [float] Moisture (water) content of urine, [wt%].

property waste_ratio#: [float] The amount of intake calories and nutrients (N, P, K) that is wasted.

Note

Not considered for Mg and Ca.